System and method for conserving power applied to an electrical apparatus

ABSTRACT

A usage pattern identifies time periods when an electrical apparatus is likely to be powered-up or not in use. Power provided to an electrical apparatus is increased during time periods that the electrical apparatus is likely to be powered-up. Similarly, the power provided to the electrical apparatus is reduced or removed during time periods that the electrical apparatus is likely to be out of use or idle. The usage pattern is continually updated and refined by collecting usage data during user interaction with the electrical apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/088,322, filed on Aug. 12, 2008, which is incorporated herein forall purposes.

TECHNICAL FIELD

Embodiments of the invention are directed to energy conservation and,more particularly, to a system and a method for adjusting power that isprovided to an electrically-powered apparatus based on a usage patternthat identifies time periods when the apparatus is likely to be used orleft idle.

BACKGROUND

An electronic computing system that includes one or more centralprocessing units (CPUs), micro-controllers or digital control systemshas a power electrical efficiency above 60% at full load when operatedat or within full capacity. When the system is idle, in between tasks,or operating at much less than full load (e.g., at 25% of full load),efficiency drops to below 20%. At a power electrical efficiency of 20%,for each ten watts of power the system requires to perform a task, fortywatts is wasted. In addition, the system may consume thirty-five wattsof power when idle, i.e., while performing no tasks. As electricityresources are becoming increasingly limited and costly, it is importantto improve the energy consumption efficiency of computing systems, notonly during full load operation, but also to improve efficiency at lessthan full load, especially when the system is left idle for an extendedperiod of time (e.g., for five minutes, multiple hours or even days).

With the popularity of personal computers, the amount of electricalpower that is wasted reaches millions to possibly billions of wattsworldwide when computing systems are idling between periods of use. Forexample, a user may not turn off the power to his computer even when thecomputer is not in use because the user may not want to wait for thecomputer to reboot after the computer is turned on. In other words, mostusers would rather leave their computers on to avoid the time delay forthe reboot process than conserve electricity. The same issue applies toother computing devices, appliances and consumer products that includemicrocontrollers or CPUs.

Therefore, it is desirable to reduce or completely remove power that isprovided to an electrically-powered apparatus when the apparatus is notin full use or is left idling for an extended period of time. It is alsodesirable to anticipate when a user is likely to operate the apparatussuch that the apparatus may be ready for immediate user interactionwithout any delay caused by powering-up the apparatus.

SUMMARY

The present invention is directed to a method and system for conservingpower applied to an electrical apparatus. The power provided to theelectrical apparatus is increased when a usage pattern identifies a timeperiod that the electrical apparatus is likely to be powered-up suchthat a user may avoid any delay in starting the electrical apparatus.Similarly, the power provided to the electrical apparatus is reduced orremoved when the usage pattern identifies a time period that theelectrical apparatus is likely to be out of use such that energy may beconserved. The usage pattern is updated and refined after repeated userinteraction with the electrical apparatus and is stored in non-volatilememory. Example data that is stored in the usage pattern associated witha computing device includes a time that the computing device is turnedon, a time duration that the user continuously interacts with thecomputing device, and a time that the computing device is turned off.Other data may also be stored in the usage pattern to restore theapparatus to a previous operational state before power was removed.

Some embodiments of the present invention are directed to a system foradjusting power applied to an electrical apparatus. The system includesan input power control unit coupled to a power source, a power supplycoupled to the input power control unit, and an electrical apparatuscommunicatively coupled to the power supply and the input power controlunit. The electrical apparatus is configured to generate a usage patternthat identifies time periods when the electrical apparatus is likely toconsume high levels of power and low levels of power. Power supplied tothe electrical apparatus by the power supply is reduced by the inputpower control unit during a time period identified by the usage patternwhen the electrical apparatus is likely to consume low levels of power.Power supplied to the electrical apparatus by the power supply isincreased by the input power control unit during a time periodidentified by the usage pattern when the electrical apparatus is likelyto consume high levels of power.

Some embodiments of the present invention are directed to a method foradjusting power applied to an electrical apparatus. The method includescollecting usage data based on user interaction with an electricalapparatus. A usage pattern generated based on the collected usage dataidentifies time periods when the electrical apparatus is likely toconsume high levels of power and low levels of power. A signal istransmitted that identifies a time period identified by the usagepattern when the electrical apparatus is likely to consume low levels ofpower and/or a time period identified by the usage pattern when theelectrical apparatus is likely to consume high levels of power. Reducedpower is received at the electrical apparatus during the time periodwhen the electrical apparatus is likely to consume low levels of power.Increased power is received at the electrical apparatus during the timeperiod when the electrical apparatus is likely to consume high levels ofpower.

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the remaining portions of thespecification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a system for adjusting powerapplied to an electrical apparatus.

FIG. 2 is a flow diagram illustrating a method performed by anelectrical apparatus for conserving power.

FIGS. 3-5 are block diagrams illustrating a system for adjusting powerapplied to an electrical apparatus.

FIG. 6 is a block diagram illustrating typical components or subsystemsof a computer apparatus that may be used in some embodiments of thepresent invention.

DETAILED DESCRIPTION

Embodiments of the invention are directed to a system and a method forconserving energy. Power that is provided to an electrically poweredapparatus or to a portion of the apparatus may be reduced when theapparatus is likely not to be in full use based on a usage pattern ofthe apparatus. Power may be entirely removed when the apparatus is leftidling for an extended period of time. In addition, power that isprovided to the apparatus or to a portion of the apparatus may beincreased when the apparatus is likely to consume more power based onthe usage pattern. The usage pattern of the apparatus is continuallyupdated and refined based on repeated user interaction with theapparatus to identify time periods during which the power provided tothe apparatus should be reduced or increased to conserve electricity.

In one embodiment, the electrically powered apparatus includesnon-volatile memory. The apparatus includes an internal clock thatmonitors real time, namely, the current time of day and the currentdate. When power provided to the apparatus is removed, data associatedwith activities performed by the apparatus during the previous usersession may be stored in the non-volatile memory. For example, theapparatus may be a personal computer, and the data stored in thenon-volatile memory may include a software program launched during theprevious user session; a web page, file or document frequently retrievedby the user; a specific website commonly accessed by the user; or anyother data related to status and usage, including the date and the timeof day just before power was removed from the apparatus. When power isreapplied to the apparatus, the apparatus may be restored to theprevious operational state before power was removed using data retrievedfrom the non-volatile memory.

When the computing device is powered-up again, the system hard drive isactivated, and the computing device resumes full operation seamlesslywithout user intervention and without the boot-up delay of prior artsystems. By storing usage data in the non-volatile memory such as datarelated to specific software programs, mode of use, network connectivityand access time, the computing device may be instantly powered up. Forexample, as soon as a user interacts with a personal computer by, e.g.,activating a power switch, touching a display screen, moving a mouse, ordepressing keys on a keyboard, power is immediately applied to theapparatus.

The usage pattern associated with the computing device may be used toanticipate when a user is likely to access the device. The usage patternis stored in the non-volatile memory and repeatedly updated and refinedas the user interacts with the computing device. Example usage data thatis stored in the usage pattern includes a time that the computing deviceis turned on, a time duration that the user continuously interacts withthe computing device, and a time that the computing device is turnedoff. Since the computing device keeps track of usage data in real time,the device may determine when user interaction is most likely to occuror not occur. This energy conserving concept may apply to any electricapparatus that is used frequently and should be turned off when not inuse to avoid wasting electricity.

FIG. 1 is a block diagram illustrating a system for adjusting powerapplied to an electrical apparatus in accordance with embodiments of theinvention. The system includes an AC power source 10, an AC input powercontrol unit 20, a power supply 30, and an electrical apparatus which isshown in the drawings as a computing device 40. The electrical apparatusmay be any device that is powered using electrical energy such as aserver, a personal computer, a kitchen appliance, a consumer electronicdevice, or any other electronic device as is known in the art. The ACpower source 10 is coupled to the AC input power control unit 20 bylines 1, 2. The AC input power control unit 20 is coupled to the powersupply 30 by lines 3, 4. The power supply 30 is coupled to the computingdevice 40 by lines 5, 6. A power management bus (PMB) 50 communicativelycouples the computing device 40 to the AC input power control unit 20and to the power supply 30.

The AC input power control unit 20 and the power supply 30 are shownseparately to highlight the function of the AC input power control unit20. However, in some embodiments, the AC input power control unit 20 maybe incorporated into the power supply 30.

Energy management software may be provided in the computing device 40 toimplement some embodiments of the invention. In addition, in someembodiments, hardware of the computing device 40 may be activated by theenergy management software to increase or reduce power applied to thecomputing device 40. The computing device 40 issues energy managementsignals to the PMB 50 based on the usage pattern associated with thecomputing device 40 to identify the level of power required forefficient operation. The AC input power control unit 20 and the powersupply 30 receive and recognize the energy management signals, and actaccordingly to reduce or increase the power provided to the computingdevice 40.

If the computing device 40 determines that no power should be appliedbased on the usage pattern, an appropriate energy management command isissued from the computing device 40 to the PMB 50 such that both the ACinput power control unit 20 and the power supply 30 are turned off. Insome embodiments, the computing device 40 may issue a signal via the PMB50 to turn off only the AC input power control unit 20 but maintain thepower supply 30 at a powered-on state. In the power-off mode, thecomputing device 40 may either turn itself off or place itself in astandby mode. In the standby mode, the computing device 40 may issue asignal to the AC input power control unit 20 via the PMB 50 to provideenough power to the power supply 30 to maintain basic timing andmonitoring functions of the computing device 40. In the standby mode,the computing device 40 may use less than 1% of the full rated power ofthe computing device 40. When the computing device 40 requires fullpower, the computing device 40 sends a power-up energy management signalto the AC input power control unit 20 and the power supply 30 via thePMB 50. The computing device 40 is then turned on and is ready torespond to user interaction.

In some embodiments, the computing device 40 recognizes whether commandsreceived via user input require the full power of the power supply 30.Thus, in some embodiments, the computing device 40 may issue energymanagement signals on the PMB 50 to control the AC input power controlunit 20 to provide the necessary amount of power from the AC powersource 10 to the power supply 30 and the computing device 40.

In some embodiments, the energy management signals are transmitted fromthe computing device 40 to the AC input power control unit 20 and thepower supply 30 via a wireless communication method. For example, thecomputing device 40 may send the energy management signals as infrared,optical or radio frequency signals. To support wireless communication,the computing device 40 is provided with an appropriate transmitter, andthe AC input power control unit 20 and the power supply 30 are providedwith corresponding receivers. Given that the distance between thecomponents is typically less than two feet, wireless communicationbetween the components can be achieved at a low cost.

FIG. 2 is a flow diagram illustrating a method performed by anelectrical apparatus for conserving power. As the electrical apparatusis used, usage data associated the electrical apparatus is continuallycollected (step 200). The usage data identifies the status and usage ofthe apparatus when certain activities are performed during a usersession. An example of usage data includes a time stamp that identifieswhen the apparatus is turned on and off, and a time duration that a usercontinuously interacts with the apparatus during the session. In theevent that the apparatus is a personal computer, other examples of usagedata may include a specific software program that is frequently executedon the personal computer; and a web site, web page, file or documentthat is frequently accessed.

The collected usage data for each user session is stored in non-volatilememory (step 210). The non-volatile memory may be a flash memory, aferromagnetic chip, or any other form of non-volatile memory known tothose having ordinary skill in the art. When the apparatus ispowered-up, the usage data is retrieved from the non-volatile memory torestore the electrical apparatus to a previous operational state beforepower was removed. For example, a computing device may launch a softwareprogram or display a web page that was active during a previous usersession before power was removed from the computing device.

A usage pattern of the electrical apparatus is updated as the usage datafor each session is collected (step 220). As additional usage data isaccumulated and stored, the usage pattern becomes more refined toidentify specific usage characteristics and operational states of theelectrical apparatus. For example, the usage pattern may be used toidentify when a user is most likely or least likely to power-up orinteract with the electrical apparatus. Similarly, the usage pattern maybe used to identify a most recent operational state of the apparatusbefore power was removed to end the previous user session of theapparatus.

As the usage pattern becomes more refined as additional usage data iscollected, the usage pattern is used to identify time periods that theelectrical apparatus is most likely or least likely to require power(step 230). In one example where the electrical apparatus is a computingdevice, a determination may be made based on the usage pattern that theuser has never accessed the computing device between 1:00 AM and 4:00 AMon a Sunday morning such that the computing device should most likely beturned off or be provided with a minimum amount of power. Similarly, theusage pattern of the computing device may be used to determine that theuser frequently accesses the computing device on a Monday atapproximately 8:00 AM to browse the Internet for thirty minutes.

After the electrical apparatus identifies time periods during which theapparatus is likely to consume the least/most power based on the usagepattern, the apparatus generates an energy management signal andtransmits the signal to the AC input power control unit and the powersupply via the power management bus (step 240). The energy managementsignal identifies the time periods during which the apparatus is likelyto consume the least/most power based on the usage pattern. For example,the signal may identify the time period between 1:00 AM and 4:00 AM on aSunday morning as the period during which the electrical apparatusrequires little or no power. Similarly, the signal may identify the timeperiod between 8:00 AM and 8:30 AM on a Monday morning as the periodduring which the electrical apparatus should be powered-up inanticipation of user interaction.

The power provided to the electrical apparatus is then reduced orincreased based on the transmitted signal (step 250). For example, whenthe electrical apparatus is a computing device that was left powered-upat 1:00 AM on Sunday, the computing device will be turned off by theoperation of the AC input power control unit and the power supply.Similarly, when 8:00 AM on a Monday approaches and the computing deviceis not powered up, the computing device will be turned on at, forexample, 7:50 AM, in response to the operation of the AC input powercontrol unit and the power supply. In some embodiments, the computingdevice may also launch an application that is most likely to be accessedby the user (e.g., an Internet browser) based on the usage pattern suchthat the application is ready for user interaction.

After the power supplied to the electrical apparatus is adjusted inresponse to the energy management signal transmitted from the electricalapparatus, processing may return to step 200 where usage data iscontinually collected at the computing device to update and furtherrefine the usage pattern. The continually updated and refined usagepattern is used to identify more precisely the time periods during whichthe computing device consumes high and low levels of power.

FIG. 3 is a block diagram illustrating a system for adjusting powerapplied to an electrical apparatus in accordance with embodiments of theinvention. The system shown in FIG. 3 is similar to the system shown inFIG. 1, however the AC input power control unit 20 is shown in moredetail. The AC input power control unit 20 includes a control unit 60, aswitch 70 and a bridge rectifier 80.

The AC power source 10 is coupled to the bridge rectifier 80 via line 1,and to the switch 70 via line 2. The switch 70 is also coupled to thebridge rectifier 80 and the control unit 60. The bridge rectifier 80 iscoupled to the power supply 30 via lines 3, 4. The power supply 30 iscoupled to the computing device 40 via lines 5, 6. The computing device40 is communicatively coupled to the power supply 30 and the controlunit 60 via the PMB 50.

The computing device 40 generates energy management signals based on thepower level required by the computing device 40 as determined by theusage pattern. The energy management signals are provided to the PMB 50.The control unit 60 receives the energy management signals from the PMB40 and controls the duty cycle of the switch 70 in response to thereceived signals. The switch 70 determines the amount of AC power thatis provided to the bridge rectifier 80. The bridge rectifier 80 convertsthe received AC power to a DC level, and provides the DC power to thepower supply 30 via lines 3, 4. The power supply 30 then provides the DCpower to the computing device 40 via lines 5, 6. As more usage data iscollected at the computing device 40 and the usage pattern becomes morerefined, the control loop repeats to continually adjust the amount ofpower that is provided to the computing device 40. As a result, powerprovided to the computing device 40 is reduced during a time period ofexpected low power consumption and is increased during a time period ofexpected high power consumption.

FIG. 4 is a block diagram illustrating a system for adjusting powerapplied to an electrical apparatus in accordance with embodiments of theinvention. The system shown in FIG. 4 is similar to the system shown inFIG. 3, but FIG. 4 shows the AC input power control unit 20 in moredetail. Specifically, the AC input power unit 20 of FIG. 4 shows thatthe bridge rectifier 80 includes rectifier diodes 21, 22 and that theswitch 70 includes switching devices 23, 24. The switching devices 23,24 and the rectifier diodes 21, 22 together form a controlled bridge.

In some embodiments the switching devices 23, 24 may each be a singletransistor (e.g., a field effect transistor (FET), a reverse blockinginsulated gate bipolar transistor (IGBT) or a bipolar transistor), or asilicon controller rectifier (SCR). As shown in FIG. 4, examples of theswitch 70 may include two anti-parallel SCRs 72 provided back to back,two anti-parallel reverse blocking IGBTs 74, and two series MOSFETs 75with two anti-parallel diodes 76. In other examples, the switch 70 mayinclude two anti-parallel gate turn-off thyristors (GTOs), or two seriesIGBTs with two anti-parallel diodes.

As shown in FIG. 4, the AC power source 10 is coupled to the anode ofthe rectifier diode 21 by line 1 and is coupled to the anode ofrectifier diode 22 by line 2. The anode of the rectifier diode 21 iscoupled to the switching device 23, and the anode of the rectifier diode22 is coupled to the switching device 24. The cathodes of the rectifierdiodes 21, 22 are coupled to each other and to the power supply 30 vialine 3. The switching devices 23, 24 are each coupled to the powersupply 30 via line 4. The control unit 60 is coupled to the switchingdevice 23 via line 25 and to the switching device 24 via line 26.

The computing device 40 transmits an energy management signal via PMB 50to adjust the amount of input power provided thereto and the energymanagement signal is provided to the control unit 60. The control unit60 routes the energy management signal via lines 25, 26 to the switchingdevices 23, 24. The energy management signal determines the duty cycleof the switching devices 23, 24 to control the amount of AC power thatis provided to the rectifier diodes 21, 22. The rectifier diodes 21, 22convert the received AC power to a DC level. The DC power is thenprovided to the power supply 30 via lines 3, 4 due to the cooperationbetween the rectifier diodes 21, 22 and the switching devices 23, 24.The power supply 30 then provides the DC power to the computing device40 via lines 5, 6. As more usage data is collected by the computingdevice 40 and the usage pattern becomes more refined, the control looprepeats to continually adjust the amount of power that is provided tothe computing device 40. As a result, power provided to the computingdevice 40 is reduced during a time period of expected low powerconsumption and is increased during a time period of expected high powerconsumption.

FIG. 5 is a block diagram illustrating a system for adjusting powerapplied to an electrical apparatus in accordance with embodiments of theinvention. The system shown in FIG. 5 is similar to the system shown inFIG. 4. However, in this embodiment, the bridge rectifier 80 includestwo rectifier diodes 27, 28 in addition to the two rectifier diodes 21,22 as shown in FIG. 4.

The cathodes of the rectifier diodes 21, 22 are coupled to the powersupply 30 via line 3. The anode of the rectifier diode 21 is coupled tothe AC power source 10 via line 1 and to the cathode of the rectifierdiode 27. The anode of the rectifier diode 22 is coupled to the AC powersource 10 via line 2 and to the cathode of the rectifier diode 28. Theanodes of the rectifier diodes 27, 28 are coupled to the switch 70.

As discussed above, the computing device 40 generates energy managementsignals based on the power level required by the computing device 40 asdetermined by the usage pattern. The energy management signals areprovided to the PMB 50. The control unit 60 receives the energymanagement signals from the PMB 40 and controls the duty cycle of theswitch 70 based on the received signals. The switch 70 determines theamount of AC power that is provided to the bridge rectifier 80. Thebridge rectifier 80 converts the AC power received from the AC powersource 10 to a DC level, and provides the DC power to the power supply30 via lines 3, 4. The power supply 30 then provides the DC power to thecomputing device 40 via lines 5, 6.

As additional usage data is collected by the computing device 40 and theusage pattern becomes more refined, the control loop repeats tocontinually adjust the amount of power that is provided to the computingdevice 40. As a result, power provided to the computing device 40 isreduced during a time period of expected low power consumption and isincreased during a time period of expected high power consumption.

FIG. 6 is a block diagram illustrating typical components or subsystemsof a computer apparatus that may be used in some embodiments of thepresent invention. Such components or any subset of such components maybe present in various components shown in the Figures including thecomputing device 40. The subsystems shown in FIG. 6 are interconnectedvia a system bus 600. Additional subsystems such as a printer 610,keyboard 620, fixed disk 630, monitor 640, which is coupled to displayadapter 650, and others are shown. Peripherals and input/output (I/O)devices, which couple to I/O controller 660, can be connected to thecomputer system by any number of means known in the art, such as serialport 670. For example, serial port 670 or external interface 680 can beused to connect the computer apparatus to a wide area network such asthe Internet, a mouse input device, or a scanner. The interconnectionvia system bus 600 allows the central processor 690 to communicate witheach subsystem and to control the execution of instructions from systemmemory 695 or the fixed disk 630, as well as the exchange of informationbetween subsystems. The system memory 695 and/or the fixed disk 630 mayembody a computer readable medium.

As disclosed above, power provided to an electrical apparatus isincreased when a usage pattern identifies a time period that theelectrical apparatus is likely to be powered-up such that a user mayavoid any delay in starting the electrical apparatus. Similarly, thepower provided to the electrical apparatus is reduced or removed whenthe usage pattern identifies a time period that the electrical apparatusis likely to be out of use or idle such that energy may be conserved.The usage pattern is refined as the user interacts with the electricalapparatus to continually adjust the amount of power that is provided tothe electrical apparatus.

While the invention has been particularly shown and described withreference to specific embodiments, it will be understood by thoseskilled in the art that the foregoing and other changes in the form anddetails may be made therein without departing from the spirit or scopeof the invention. Therefore, the scope of this invention should not belimited to the embodiments described above, and should instead bedefined by the following claims.

1. An input power unit for controlling power supplied to an electricalapparatus which is coupled to a direct current power supply, the inputpower unit comprising: input terminals adapted to be connected to asource of alternating current; a switch coupled to the input terminals;a control unit connected to provide control signals to the switch; arectifier connected to the switch; a power management bus coupled to thecontrol unit, the direct current power supply and the electricalapparatus, wherein: the rectifier comprises a pair of diodes, eachhaving an anode and a cathode; the input terminals are coupled torespective anodes of each of the pair of diodes; the cathodes of thepair of diodes are coupled together and to a first input terminal of thedirect current power supply; the switch is coupled to each of the anodesand to a second in gut tee the direct current power supply; and wherein:in response to energy management signals regarding the electricalapparatus provided on the power management bus, the control unitprovides signals to the switch to provide changing amounts ofalternating current to the rectifier, and the rectifier in responseprovides controlled amounts of direct current ranging from a maximumvalue to zero to the direct current power supply.
 2. The input powerunit of claim 1 wherein the electrical apparatus is configured to:collect usage data based on user interaction with the electricalapparatus; and update a usage pattern based on the collected usage data.3. The input power unit of claim 2 wherein the electrical apparatus isconfigured to store the usage data in a non-volatile memory.
 4. Theinput power unit of claim 3 wherein the usage data comprises at leastone of a group consisting of: a time that the electrical apparatus isturned on, a time that the electrical apparatus is turned off, and atime duration that a user continuously interacts with the electricalapparatus.
 5. The input power unit of claim 4 wherein the electricalapparatus comprises a computing device.
 6. The input power unit of claim5 wherein the usage data comprises an operational state of the computingdevice before power was previously removed from the computing device,the usage data comprising at least one of a group consisting of: asoftware program launched during a user session before power waspreviously removed from the computing device, a web page accessed duringthe user session before power was previously removed from the computingdevice, and a file accessed during a user session before power waspreviously removed from the computing device.
 7. The input power unit ofclaim 6 wherein, in response to increasing power supplied to thecomputing device during a time period of likely high power consumption,the computing device is restored to the operational state before powerwas previously removed from the computing device.
 8. The input powerunit of claim 7 wherein no power is supplied to the electrical apparatusduring the time period when the electrical apparatus is likely toconsume low levels of power.
 9. The input power unit of claim 2 wherein:power supplied to the electrical apparatus by the direct current powersupply is reduced by the input power control unit during a time periodidentified by the usage pattern when the electrical apparatus is likelyto consume low levels of power; and power supplied to the electricalapparatus by the direct current power supply is increased by the inputpower control unit during a time period identified by the usage patternwhen the electrical apparatus is likely to consume high levels of power.10. An input power unit as in claim 1 wherein: the control unit controlsa duty cycle of the switch in response to the energy management signalsreceived from the electrical apparatus; and wherein the duty cycle ofthe switch determines the amount of power provided to the rectifier. 11.An input power unit as in claim 10 wherein: the electrical apparatusgenerates a usage pattern which identifies time periods when theelectrical apparatus is likely to use differing amounts of power andprovides that information to the control unit; and in response thecontrol unit provides control signals to the switch to control directcurrent from the rectifier in accordance with likely power use of theelectrical apparatus.
 12. An input power unit as in claim 11 wherein therectifier comprises a bridge rectifier.
 13. An input power unit as inclaim 12 wherein the switch comprises at least one of a transistor, adiode and a thyristor.
 14. The input power unit of claim 13 wherein theswitch comprises a pair of transistors coupled together.
 15. The inputpower unit of claim 13 wherein the switch comprises a pair of diodescoupled together.
 16. In a system having an input power unit forcontrolling power supplied to an electrical apparatus which is coupledto a direct current power supply, the input power unit including inputterminals adapted to be connected to a source of alternating current, aswitch coupled to the input terminals, a control unit connected toprovide control signals to the switch, a rectifier connected to theswitch, a power management bus coupled to the control unit, the directcurrent power supply and the electrical apparatus, in which in responseto energy management signals regarding the electrical apparatus providedon the power management bus, the control unit provides signals to theswitch to provide changing amounts of alternating current to therectifier, the controlled amounts ranging from a maximum value to zero,and the rectifier in response provides controlled amounts of directcurrent to the direct current power supply, and wherein the rectifiercomprises a pair of diodes, each having an anode and a cathode; theinput terminals are coupled to respective anodes of each of the pair ofdiodes; the cathodes of the pair of diodes are coupled together and to afirst input terminal of the direct current power supply; and the switchcoupled to each of the anodes and to a second input terminal of thedirect current power supple a method comprising: collecting usage databased on user interaction with an electrical apparatus; generating ausage pattern based on the collected usage data, wherein the usagepattern identifies time periods when the electrical apparatus is likelyto consume high levels of power and low levels of power; transmitting asignal identifying at least one of: a time period identified by theusage pattern when the electrical apparatus is likely to consume lowlevels of power and a time period identified by the usage pattern whenthe electrical apparatus is likely to consume high levels of power;receiving reduced power at the electrical apparatus during the timeperiod when the electrical apparatus is likely to consume low levels ofpower; and receiving increased power at the electrical apparatus duringthe time period when the electrical apparatus is likely to consume highlevels of power.
 17. The method of claim 16, further comprising:collecting additional usage data based on additional user interactionwith the electrical apparatus; and updating the usage pattern based onthe collected additional usage data.
 18. The method of claim 16, whereinthe electrical apparatus comprises a computing device, the methodfurther comprising: in response to increasing power supplied to thecomputing device during a time period of likely high levels of powerconsumption, restoring the computing device to an operational statebefore power was previously removed from the computing device.